Vehicle control device

ABSTRACT

A vehicle control device can be mounted in a vehicle. A receiver receives information from a wireless device mounted in another vehicle. A determiner determines whether or not to switch an automatic steering mode to a manual steering mode on the basis of the information received by the receiver. A notifier prompts a driver of the vehicle to switch the automatic steering mode to the manual steering mode in a case where the determiner determines to switch the automatic steering mode to the manual steering mode.

BACKGROUND

1. Technical Field

The present disclosure relates to a vehicle control technique. Morespecifically, the present disclosure relates to a vehicle control devicethat determines whether or not to switch an automatic steering mode to amanual steering mode.

2. Description of the Related Art

A vehicle that is running in an automatic steering mode switches fromthe automatic steering mode to a manual steering mode by handing overauthority to operate the vehicle to a driver in a case where it isdetermined that it is difficult to continue the automatic steering mode(see, for example, Japanese Unexamined Patent Application PublicationNo. 2011-131838).

SUMMARY

In one general aspect, the techniques disclosed here feature a vehiclecontrol device that is capable of being mounted in a vehicle, including:a receiver that receives information from a wireless device mounted inanother vehicle; a determiner that determines whether or not to switchan automatic steering mode to a manual steering mode on basis of theinformation received by the receiver; and a notifier that prompts adriver of the vehicle to switch the automatic steering mode to themanual steering mode in a case where the determiner determines to switchthe automatic steering mode to the manual steering mode.

According to the present disclosure, the automatic steering mode can besmoothly switched to the manual steering mode.

It should be noted that general or specific embodiments may beimplemented as a system, a method, an integrated circuit, a computerprogram, a storage medium, or any selective combination thereof.

Additional benefits and advantages of the disclosed embodiments willbecome apparent from the specification and drawings. The benefits and/oradvantages may be individually obtained by the various embodiments andfeatures of the specification and drawings, which need not all beprovided in order to obtain one or more of such benefits and/oradvantages.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a configuration of a communicationsystem according to Embodiment 1 of the present disclosure;

FIG. 2 is a diagram illustrating a configuration of a base stationdevice of FIG. 1;

FIG. 3 is a diagram illustrating a format of a frame defined in thecommunication system of FIG. 1;

FIG. 4 is a diagram illustrating a configuration of a terminal device ofFIG. 1;

FIG. 5 is a diagram illustrating a configuration of a vehicle accordingto Embodiment 1 of the present disclosure;

FIG. 6 is a diagram illustrating transition among modes managed in aprocess unit of FIG. 5;

FIG. 7 is a diagram for explaining an outline of a process performed bythe process unit of FIG. 5;

FIG. 8 is a flow chart illustrating a procedure of processes performedby a vehicle control device of FIG. 5 in an automatic steering mode;

FIG. 9 is a flow chart illustrating a procedure of processes performedby the vehicle control device of FIG. 5 in a switching mode;

FIG. 10 is a diagram illustrating a configuration of a vehicle accordingto Embodiment 2 of the present disclosure;

FIG. 11 is a diagram for explaining an outline of a process performed bya process unit of FIG. 10;

FIG. 12 is a sequence diagram illustrating a merging procedure performedbetween vehicles according to Embodiment 2 of the present disclosure;

FIG. 13 is a sequence diagram illustrating another merging procedureperformed among vehicles according to Embodiment 2 of the presentdisclosure; and

FIG. 14 is a flow chart illustrating a procedure for generatingtravelling schedule information in the vehicle control device accordingto Embodiment 2 of the present disclosure.

DETAILED DESCRIPTION Underlying Knowledge Forming Basis of the PresentDisclosure

In a case where an automatic steering mode is executed only on the basisof a result of detection of an autonomous sensor provided in a vehicle,an area used to determine whether or not to continue the automaticsteering mode is limited to an area that can be detected by theautonomous sensor. The autonomous sensor is, for example, a camera or amillimeter-wave radar. In general, the area that can be detected by theautonomous sensor is approximately several tens of meters. Accordingly,a period from a time when it is determined that continuation of theautomatic steering mode is difficult to a time when the automaticsteering mode should be switched to a manual steering mode is short. Inview of this, it is desired that switching from the automatic steeringmode to the manual steering mode be smoothly executed.

The present disclosure was accomplished in view of such a circumstanceand provides a technique for smoothly switching the automatic steeringmode to the manual steering mode.

Embodiment 1

An outline of the present disclosure is described below before thepresent disclosure is specifically described. Embodiment 1 of thepresent disclosure relates to a vehicle control device mounted in avehicle that is capable of switching between an automatic steering modeand a manual steering mode. The vehicle control device proposesswitching from the automatic steering mode to the manual steering modeto a driver of the vehicle in a case where it is determined thatcontinuation of the automatic steering mode is difficult. In a casewhere the driver agrees with the proposal, the vehicle control deviceswitches the automatic steering mode to the manual steering mode.Conventionally, whether or not continuation of the automatic steeringmode is difficult is determined on the basis of a result of detection byan autonomous sensor. The autonomous sensor is, for example, a camera ora millimeter-wave radar. However, since a detection range of theautonomous sensor is short (approximately several tens of meters), adriver of the vehicle is required to hastily execute the switching. Inorder to execute smooth switching, the vehicle control device accordingto the present embodiment performs the determining process on the basisof information acquired in a communication system such as ITS(Intelligent Transport Systems).

The ITS are communication systems in which inter-vehicle communicationis performed between terminal devices mounted in vehicles androadside-to-vehicle communication from a base station device provided atan intersection or the like to a terminal device is performed. Thecommunication systems use wireless LAN (Local Area Network) complyingwith a standard such as IEEE802.11 and an access control function calledCSMA/CA (Carrier Sense Multiple Access with Collision Avoidance).Accordingly, the same wireless channel is shared by a plurality ofterminal devices. In the ITS, it is necessary to transmit information toa large indefinite number of terminal device. In order to efficientlyexecute such transmission, the present communication system broadcasts apacket signal.

That is, a terminal device broadcasts, as inter-vehicle communication, apacket signal in which information such as the speed or position of avehicle is stored. Another terminal device receives the packet signaland recognizes the approach or the like of the vehicle on the basis ofthe information. In order to reduce interference betweenroadside-to-vehicle communication and inter-vehicle communication, abase station device repeatedly defines a frame including a plurality ofsub-frames. The base station device selects, for roadside-to-vehiclecommunication, any of the plurality of sub-frames, and broadcasts apacket signal in which control information and the like are storedduring a period corresponding to the start portion of the selectedsub-frame.

The control information includes information concerning a period(hereinafter referred to as a “roadside-to-vehicle communicationperiod”) for broadcast transmission of the packet signal by the basestation device. A terminal device specifies a roadside-to-vehiclecommunication period on the basis of the control information and thenbroadcasts a packet signal by the CSMA method during a period(hereinafter referred to as an “inter-vehicle communication period”)other than the roadside-to-vehicle communication period. As a result,the roadside-to-vehicle communication and the inter-vehiclecommunication are time-division multiplexed. Note that a terminal devicethat cannot receive the control information from the base stationdevice, i.e., a terminal device that is out of an area formed by thebase station device transmits a packet signal by the CSMA methodirrespective of the configuration of the frame. In such a communicationsystem, a distance of transmission of a packet signal is longer than adistance of detection by an autonomous sensor, and therefore a timing ofdetermination can be made earlier.

A vehicle control device according to the present embodiment isdescribed after a communication system used in the vehicle controldevice is described. FIG. 1 is a diagram illustrating a configuration ofa communication system 100 according to Embodiment 1 of the presentdisclosure. This corresponds to a case where an intersection is viewedfrom above. The communication system 100 includes a base station device10; a first vehicle 12 a, a second vehicle 12 b, a third vehicle 12 c, afourth vehicle 12 d, a fifth vehicle 12 e, a sixth vehicle 12 f, aseventh vehicle 12 g, and an eighth vehicle 12 h, which are collectivelyreferred to as vehicles 12; and a network 202. In FIG. 1, only aterminal device 14 mounted in the first vehicle 12 a is illustrated, buta terminal device 14 is mounted in each of the vehicles 12. Furthermore,an area 212 is formed around the base station device 10, and an outsidearea 214 is formed outside the area 212.

As illustrated in FIG. 1, a road extending in a horizontal direction,i.e., a left-right direction of FIG. 1 crosses, at a central part, aroad extending in a vertical direction, i.e., an top-bottom direction ofFIG. 1. In FIG. 1, the top side corresponds to “north”, the left sidecorresponds to “west”, the bottom side corresponds to “south”, and theright side corresponds to “east”. A part at which these two roads crosseach other is an “intersection”. The first vehicle 12 a and the secondvehicle 12 b are traveling from left to right, and the third vehicle 12c and the fourth vehicle 12 d are traveling from right to left. Thefifth vehicle 12 e and the sixth vehicle 12 f are traveling from top tobottom, and the seventh vehicle 12 g and the eighth vehicle 12 h aretraveling from bottom to top.

In the communication system 100, the base station device 10 is fixedlyinstalled at the intersection. The base station device 10 controlscommunication between the terminal devices. The base station device 10repeatedly generates a frame including a plurality of sub-frames on thebasis of a signal received from a GPS (Global Positioning System)satellite (not illustrated) or a frame formed by another base stationdevice 10 (not illustrated). It is specified that a roadside-to-vehiclecommunication period can be set at the start of each of the sub-frames.

The base station device 10 selects a sub-frame in which noroadside-to-vehicle communication period is set by another base stationdevice 10 from among the plurality of sub-frames included in the frame.The base station device 10 sets a roadside-to-vehicle communicationperiod at the start of the selected sub-frame. The base station device10 broadcasts a packet signal during the set roadside-to-vehiclecommunication period. A plurality of packet signals may be broadcastduring the roadside-to-vehicle communication period. The packet signalincludes, for example, accident information, traffic jam information,and traffic signal information. Note that the packet signal alsoincludes information concerning a timing at which theroadside-to-vehicle communication period is set and control informationconcerning the frame.

The terminal device 14 is mounted in each of the vehicles 12 asdescribed above and can therefore be transported. Upon receipt of thepacket signal from the base station device 10, the terminal device 14estimates that the terminal device 14 is within the area 212. In a casewhere the terminal device 14 is within the area 212, the terminal device14 generates a frame on the basis of control information included in thepacket signal, especially information concerning a timing at which theroadside-to-vehicle communication period is set and informationconcerning the frame. As a result, the frame generated in each of theplurality of terminal devices 14 is in synchronization with the framegenerated in the base station device 10. The terminal device 14broadcasts a packet signal during an inter-vehicle communication periodthat is different from the roadside-to-vehicle communication period.During the inter-vehicle communication period, CSMA/CA is performed.Meanwhile, in a case where the terminal device 14 estimates that theterminal device 14 is within the outside area 214, the terminal device14 broadcasts a packet signal by performing CSMA/CA irrespective of theconfiguration of the frame. The terminal device 14 recognizes anapproach or the like of a vehicle 12 in which another terminal device 14is mounted on the basis of a packet signal from the other terminaldevice 14. Details of the recognition will be described later.

FIG. 2 illustrates a configuration of the base station device 10. Thebase station device 10 includes an antenna 20, an RF unit 22, a modemunit 24, a process unit 26, a control unit 28, and a networkcommunication unit 30. The process unit 26 includes a frame control unit32, a selection unit 34, and a generation unit 36.

The RF unit 22 receives, as a receiving process, a packet signal from aterminal device 14 or another base station device 10 (not illustrated)via the antenna 20. The RF unit 22 converts the frequency of thereceived wireless frequency packet signal to generate a baseband packetsignal. Furthermore, the RF unit 22 supplies the baseband packet signalto the modem unit 24. In general, the baseband packet signal is made upof an in-phase component and an orthogonal component, and therefore twosignal lines should be illustrated. However, for clarity in FIG. 2, onlyone signal line is illustrated. The RF unit 22 includes an LNA (LowNoise Amplifier), a mixer, an AGC, and an A/D converter unit.

The RF unit 22 converts, as a transmitting process, the frequency of thebaseband packet signal supplied from the modem unit 24 to generate awireless frequency packet signal. Furthermore, the RF unit 22 transmitsthe wireless frequency packet signal via the antenna 20 during theroadside-to-vehicle communication period. The RF unit 22 includes a PA(Power Amplifier), a mixer, and a D/A converter unit.

The modem unit 24 demodulates, as a receiving process, the basebandpacket signal from the RF unit 22. Furthermore, the modem unit 24supplies a demodulation result to the process unit 26. Moreover, themodem unit 24 modulates, as a transmitting process, data from theprocess unit 26. Furthermore, the modem unit 24 supplies, as a basebandpacket signal, a modulation result to the RF unit 22. Since thecommunication system 100 supports an OFDM (Orthogonal Frequency DivisionMultiplexing) modulation method, the modem unit 24 also performs, as areceiving process, FFT (Fast Fourier Transform) and performs, as atransmitting process, IFFT (Inverse Fast Fourier Transform).

The frame control unit 32 receives a signal from a GPS satellite (notillustrated) and acquires time information on the basis of the receivedsignal. Note that acquisition of the time information can be performedby using a known art, and description thereof is omitted. The framecontrol unit 32 generates a plurality of frames on the basis of the timeinformation. For example, the frame control unit 32 generates 10 framesof “100 msec” by dividing a period of “1 sec” into 10 sections on thebasis of a timing indicated in the time information. By repeating such aprocess, a frame is repeatedly defined. Note that the frame control unit32 may detect control information from the demodulation result andgenerate a frame on the basis of the detected control information. Sucha process corresponds to generating a frame that is in synchronizationwith a timing of a frame generated by another base station device 10.

FIG. 3 illustrates a format of a frame defined in the communicationsystem 100. FIG. 3(a) illustrates a configuration of the frame. Theframe is made up of N sub-frames, i.e., the first through N-thsub-frames. That is, it can be said that the frame is formed bytime-multiplexing a plurality of sub-frames that can be used forbroadcast of a packet signal by the terminal device 14. For example, ina case where the length of the frame is 100 msec and where N is 8,sub-frames each having a length of 12.5 msec are defined. N may be anumber other than 8. FIGS. 3(b) through 3(d) are described later. SeeFIG. 2 again.

The selection unit 34 selects a sub-frame in which a roadside-to-vehiclecommunication period should be set from among the plurality ofsub-frames included in the frame. Specifically, the selection unit 34accepts the frame defined by the frame control unit 32. Furthermore, theselection unit 34 accepts an instruction concerning the selectedsub-frame via an interface (not illustrated). The selection unit 34selects a sub-frame corresponding to the instruction. Separately fromthis, the selection unit 34 may automatically select a sub-frame. Inthis case, the selection unit 34 receives a demodulation result fromanother base station device 10 or a terminal device 14 (not illustrated)via the RF unit 22 and the modem unit 24. The selection unit 34 extractsthe demodulation result received from the other base station device 10.The selection unit 34 specifies a sub-frame for which the demodulationresult has not been accepted by specifying a sub-frame for which thedemodulation result has been accepted.

This corresponds to specifying a sub-frame in which aroadside-to-vehicle communication period has not been set by anotherbase station device 10, i.e., an unused sub-frame. In a case where thereare a plurality of unused sub-frames, the selection unit 34 randomlyselects one sub-frame. In a case where there is no unused sub-frame,i.e., in a case where each of the plurality of sub-frames is being used,the selection unit 34 acquires reception electric power corresponding tothe demodulation result and preferentially selects a sub-frame of smallreception electric power.

FIG. 3(b) illustrates a configuration of a frame generated by a firstbase station device 10 a (not illustrated). The first base stationdevice 10 a sets a roadside-to-vehicle communication period at the startof a first sub-frame. Furthermore, the first base station device 10 asets an inter-vehicle communication period in a period of the firstsub-frame excluding a roadside-to-vehicle communication period and inthe second to N-th sub-frames. The inter-vehicle communication period isa period in which the terminal device 14 can broadcast a packet signal.That is, it is specified that the first base station device 10 a canbroadcast a packet signal during the roadside-to-vehicle communicationperiod, which is the start of the first sub-frame, and the terminaldevice 14 can broadcast a packet signal during an inter-vehiclecommunication period other than the roadside-to-vehicle communicationperiod in the frame.

FIG. 3(c) illustrates a configuration of a frame generated by a secondbase station device 10 b (not illustrated). The second base stationdevice 10 b sets a roadside-to-vehicle communication period at the startof a second sub-frame. Furthermore, the second base station device 10 bsets an inter-vehicle communication period in a period of the secondsub-frame excluding the roadside-to-vehicle communication period, thefirst sub-frame, and the third sub-frame through the N-th sub-frame.FIG. 3(d) illustrates a configuration of a frame generated by a thirdbase station device 10 c (not illustrated). The third base stationdevice 10 c sets a roadside-to-vehicle communication period at the startof the third sub-frame. Furthermore, the third base station device 10 csets an inter-vehicle communication period in a period of the thirdsub-frame excluding the roadside-to-vehicle communication period, thefirst sub-frame, the second sub-frame, and the fourth sub-frame throughthe N-th sub-frame. In this way, the plurality of base station devices10 select different sub-frames and set a roadside-to-vehiclecommunication period at the start of the selected sub-frames. See FIG. 2again. The selection unit 34 supplies a number of the selected sub-frameto the generation unit 36.

The generation unit 36 receives the number of the sub-frame from theselection unit 34. The generation unit 36 sets a roadside-to-vehiclecommunication period in the sub-frame having the received sub-framenumber, and generates a packet signal that should be broadcast in theroadside-to-vehicle communication period. In a case where a plurality ofpacket signals are transmitted during one roadside-to-vehiclecommunication period, the generation unit 36 generates these packetsignals. A packet signal is made up of control information and apayload. The control information includes, for example, a number of asub-frame in which a roadside-to-vehicle communication period has beenset. The payload includes, for example, accident information, trafficjam information, and traffic signal information. These data are acquiredfrom the network 202 (not illustrated) by the network communication unit30. The process unit 26 causes the modem unit 24 and the RF unit 22 tobroadcast a packet signal during the roadside-to-vehicle communicationperiod. The control unit 28 controls the process of the whole basestation device 10.

This configuration is realized by a CPU, memory, and other LSI of anycomputer in the case of hardware and is realized by a program loaded tomemory in the case of software. In FIG. 2, functional blocks realized bycooperation of these are illustrated. Therefore, it is understood by aperson skilled in the art that these functional blocks are realized invarious forms by hardware only or by a combination of hardware andsoftware.

FIG. 4 illustrates a configuration of the terminal device 14. Theterminal device 14 includes an antenna 50, an RF unit 52, a modem unit54, a process unit 56, and a control unit 58. The process unit 56includes a timing determination unit 60, a forwarding determination unit62, a positional information acquisition unit 64, a generation unit 66,and a notification unit 70. The timing determination unit 60 includes anextraction unit 72 and a carrier sense unit 74. The terminal device 14can be mounted in each of the vehicles 12 as described above. Theantenna 50, the RF unit 52, and the modem unit 54 perform similarprocesses to the antenna 20, the RF unit 22, and the modem unit 24 ofFIG. 2. The following discusses mainly differences.

The modem unit 54 and the process unit 56 receive, in a receivingprocess, a packet signal from another terminal device 14 or the basestation device 10 (not illustrated). As described above, the modem unit54 and the process unit 56 receive a packet signal from the base stationdevice 10 during a roadside-to-vehicle communication period, and receivea packet signal from another terminal device 14 during an inter-vehiclecommunication period. The packet signal from another terminal device 14includes at least the current position, traveling direction, travelingspeed, and the like (hereinafter collectively referred to as “positionalinformation”) of another vehicle 12 in which another terminal device 14is mounted. Acquisition of positional information of another terminaldevice 14 can be performed by using a known technique, and descriptionthereof is omitted.

In a case where a demodulation result supplied from the modem unit 54 isa packet signal from the base station device 10 (not illustrated), theextraction unit 72 specifies a timing of a sub-frame in which aroadside-to-vehicle communication period is set. In this case, theextraction unit 72 estimates that the terminal device 14 is within thearea 212 of FIG. 1. The extraction unit 72 generates a frame on thebasis of the timing of the sub-frame and the contents of a messageheader of the packet signal, specifically, the contents of theroadside-to-vehicle communication period. Note that generation of theframe is performed in the same manner as the frame control unit 32, anddescription thereof is omitted. As a result, the extraction unit 72generates a frame that is in synchronization with the frame generated inthe base station device 10. In a case where a source of broadcast of thepacket signal is another terminal device 14, the extraction unit 72omits a process of generating a synchronized frame, but extractspositional information included in the packet signal and supplies theextracted positional information to the notification unit 70.

Meanwhile, in a case where the packet signal from the base stationdevice 10 is not received, the extraction unit 72 estimates that theterminal device 14 is within the outside area 214 of FIG. 1. In a casewhere the extraction unit 72 estimates that the terminal device 14 iswithin the area 212, the extraction unit 72 selects an inter-vehiclecommunication period. In a case where the extraction unit 72 estimatesthat the terminal device 14 is within the outside area 214, theextraction unit 72 selects a timing that is not related to theconfiguration of the frame. In a case where the extraction unit 72selects the inter-vehicle communication period, the extraction unit 72supplies information concerning timings of the frame and the sub-frameand the inter-vehicle communication period to the carrier sense unit 74.In a case where the extraction unit 72 selects a timing that is notrelated to the configuration of the frame, the extraction unit 72instructs the carrier sense unit 74 to perform carrier sense.

The carrier sense unit 74 accepts the information concerning timings ofthe frame and the sub-frame and the inter-vehicle communication periodfrom the extraction unit 72. The carrier sense unit 74 determines atransmission timing by starting CSMA/CA during the inter-vehiclecommunication period. Meanwhile, in a case where the carrier sense unit74 is instructed by the extraction unit 72 to perform carrier sense thatis not related to the configuration of the frame, the carrier sense unit74 determines a transmission timing by performing CSMA/CA withoutconsidering the configuration of the frame. The carrier sense unit 74notifies the modem unit 54 and the RF unit 52 of the determinedtransmission timing and causes the modem unit 54 and the RF unit 52 tobroadcast a packet.

The forwarding determination unit 62 controls transfer of the controlinformation. The forwarding determination unit 62 extracts informationto be transferred from the control information. The forwardingdetermination unit 62 generates information that should be transferredon the basis of the extracted information. Description of this processis omitted. The forwarding determination unit 62 supplies theinformation that should be transferred, i.e., part of the controlinformation to the generation unit 66.

The positional information acquisition unit 64 includes a GPS receiver,a gyroscope, a vehicle speed sensor, and the like (not illustrated), andacquires the current position, travelling direction, traveling speed,and the like (collectively referred to as “positional information” asdescribed above) of the vehicle 12 (not illustrated), i.e., the vehicle12 in which the terminal device 14 is mounted on the basis of datasupplied from the GPS receiver, the gyroscope, the vehicle speed sensor,and the like. The current position is indicated by latitude andlongitude. The acquisition of the current position, travellingdirection, traveling speed, and the like can be performed by using aknown art, and description thereof is omitted. The positionalinformation may include the current position, traveling speed, and thelike of a vehicle around (e.g., a vehicle running ahead or behind)detected by the vehicle 12 in which the terminal device 14 is mounted byusing the autonomous sensor or the like. The positional informationacquisition unit 64 supplies the positional information to thegeneration unit 66.

The generation unit 66 accepts the positional information from thepositional information acquisition unit 64 and accepts part of thecontrol information from the forwarding determination unit 62. Thegeneration unit 66 generates a packet signal including these pieces ofinformation and broadcasts the generated packet signal via the modemunit 54, the RF unit 52, and the antenna 50 at the transmission timingdetermined by the carrier sense unit 74. This corresponds tointer-vehicle communication.

The notification unit 70 receives the positional information from thepositional information acquisition unit 64 and receives the positionalinformation from the extraction unit 72. The former positionalinformation corresponds to the positional information of the othervehicle 12, and the latter positional information corresponds to thepositional information of the host vehicle 12. The notification unit 70determines the presence or absence of collision between the host vehicle12 and the other vehicle 12 on the basis of the positional informationof the host vehicle 12 and the positional information of the othervehicle 12. A known technique can be used to determine the presence orabsence of collision. For example, a future position is estimated on thebasis of the current position of the host vehicle 12 in consideration ofthe traveling direction and the traveling speed, and a future positionis estimated on the basis of the current position of the other vehicle12 in consideration of the traveling direction and the traveling speed.

The notification unit 70 determines that collision occurs in a casewhere the future positions of the host vehicle 12 and the other vehicle12 are close to each other and determines that collision does not occurin the other cases. A case where the future positions of the hostvehicle 12 and the other vehicle 12 are close to each other correspondsto a case where a distance between the future positions of the hostvehicle 12 and the other vehicle 12 is shorter than a threshold value,and a case where the future positions of the host vehicle 12 and theother vehicle 12 are not close to each other corresponds to the othercases. Such determination is performed regularly, for example, atintervals of 100 msec, which is a frame period. The notification unit 70notifies a driver of a determination result by using a display or aspeaker (not illustrated). Furthermore, the notification unit 70 maynotify the driver of information included in a packet signal suppliedfrom another terminal device 14 or the base station device 10 by usingthe display or the speaker.

FIG. 5 is a diagram illustrating a configuration of a vehicle 12according to Embodiment 1 of the present disclosure. FIG. 5 illustratesespecially a configuration related to automatic driving. The vehicle 12includes the terminal device 14, a vehicle control device 300, anautomatic driving control device 302, a display unit 304, and a modeswitch 306. The vehicle control device 300 includes an I/O unit 310 anda process unit 312, and the process unit 312 includes a receiving unit330, a determining unit 332, and a notification unit 334. The automaticdriving control device 302 includes an I/O unit 320 and a process unit322.

The terminal device 14 is configured as described above. The terminaldevice 14 supplies, to the I/O unit 310, positional information includedin a packet signal received from another terminal device 14, i.e.,positional information of another vehicle 12. The terminal device 14also supplies positional information thereof to the I/O unit 310. Thedisplay unit 304 visually notifies a driver of information for thedriver and is, for example, a display of a car navigation device or adisplay audio device. The display unit 304 may be an HUD (Head UpDisplay) for displaying an image on a windshield or may be a display ofa smartphone or a tablet that is provided on a dashboard and operates inassociation with the vehicle control device 300 that will be describedlater. The display unit 304 may be the display on which the notificationunit 70 of the terminal device 14 displays information.

The mode switch 306 is a switch that is operated by a driver and is aswitch for switching between an automatic steering mode and a manualsteering mode. A switching signal from the mode switch 306 istransmitted to the vehicle control device 300 through a signal line.

The automatic driving control device 302 is an automatic driving controlhaving an automatic driving control function. The configuration of theprocess unit 322 can be realized by cooperation of a hardware resourceand a software resource or only by a hardware resource. A processor, aROM, a RAM, and other LSI can be used as the hardware resource, andprograms such as an operating system, an application, and firmware canbe used as the software resource. The I/O unit 320 performs variouskinds of communication control processes according to various kinds ofcommunication formats.

The vehicle control device 300 is a control for executing a driving modedetermining function. The process unit 312 can be realized bycooperation of a hardware resource and a software resource or only by ahardware resource. A processor, a ROM, a RAM, and other LSI can be usedas the hardware resource, and programs such as an operating system, anapplication, and firmware can be used as the software resource. The I/Ounit 310 performs various kinds of communication control processesaccording to various kinds of communication formats. The vehicle controldevice 300 and the automatic driving control device 302 are directlyconnected to each other through a signal line. Note that the vehiclecontrol device 300 and the automatic driving control device 302 may beconnected to each other over a CAN (Controller Area Network). Thevehicle control device 300 and the automatic driving control device 302may be united as a single control.

The process unit 312 manages driving modes of the automatic drivingcontrol device 302. In this example, the automatic steering mode, themanual steering mode, and a switching mode are defined as the drivingmodes. The automatic steering mode is, for example, a mode in which thevehicle 12 is in charge of driving. The manual steering mode is, forexample, a mode in which the driver drives the vehicle 12. FIG. 6 is adiagram illustrating transition among the modes managed in the processunit 312. As illustrated in FIG. 6, the switching mode is provided at apoint in transition from the automatic steering mode to the manualsteering mode in order to avoid direct switching from the automaticsteering mode and the manual steering mode. This is because it isdifficult for the driver to react if direct switching from the automaticsteering mode to the manual steering mode occurs. Meanwhile, even in acase where direct switching from the manual steering mode to theautomatic steering mode occurs, the driver can react, and therefore noswitching mode is provided anywhere in transition from the manualsteering mode to the automatic steering mode.

A line L1 indicates state transition from the automatic steering mode tothe switching mode that occurs in a case where it is determined that theautomatic steering mode will not be able to be maintained after elapseof several seconds or after traveling several meters. A line L2indicates state transition from the switching mode to the automaticsteering mode that occurs in a case where it is determined that theautomatic steering mode is executable. A line L3 indicates statetransition from the switching mode to the manual steering mode thatoccurs in a case where the mode switch 306 is pressed down by thedriver.

A line L4 indicates state transition from the manual steering mode tothe manual steering mode that occurs in a case where the driver switchesthe manual steering mode to the automatic steering mode but it isdetermined that the automatic steering mode is not executable. A line L5indicates state transition from the manual steering mode to theautomatic steering mode that occurs in a case where the driver switchesthe manual steering mode to the automatic steering mode and it isdetermined that the automatic steering mode is executable. A determiningprocess in the line L1 is described below. See FIG. 5 again.

The receiving unit 330 receives the positional information of the hostvehicle 12 from the terminal device 14 via the I/O unit 310. Thiscorresponds to receiving the positional information acquired by thepositional information acquisition unit 64. As described above, thepositional information includes at least information such as the currentposition, travelling direction, and travelling speed. For convenience ofdescription, this positional information is referred to as “firstpositional information”. Furthermore, the receiving unit 330 receivespositional information of another vehicle 12 from the terminal device 14via the I/O unit 310. This corresponds to receiving positionalinformation included in a packet signal transmitted from anotherterminal device 14 mounted in the other vehicle 12. For convenience ofdescription, this positional information is referred to as “secondpositional information”. The second positional information may includeinformation concerning a traffic lane on which the other vehicle 12 isrunning in addition to the information included in the first positionalinformation. The receiving unit 330 supplies the first positionalinformation and the second positional information to the determiningunit 332.

The determining unit 332 receives the first positional information andthe second positional information from the receiving unit 330. Thedetermining unit 332 determines whether or not to switch the automaticsteering mode to the manual steering mode on the basis of the firstpositional information and the second positional information receivedfrom the receiving unit 330. This determining process is described withreference to FIG. 7. FIG. 7 is a diagram for explaining an outline ofthe process performed by the process unit 312. More specifically, FIGS.7(a) and 7(b) are diagrams each illustrating a scene where a vehiclemerges into a main lane on an expressway or the like. A first vehicle 12a in FIG. 7(a) corresponds to the host vehicle 12. The first vehicle 12a is running on a merging lane in the automatic steering mode, andsecond through seventh vehicles 12 b through 12 g (hereinafter sometimescollectively referred to as “other vehicles 12”) are running on the mainlane. The first vehicle 12 a is trying to merge from the merging laneinto the main lane. The terminal device 14 mounted in the first vehicle12 a exchanges positional information with the other terminal device 14mounted in the other vehicle 12. Thus, the determining unit 332 receivesthe first positional information and the second positional informationas described above.

The determining unit 332 recognizes a situation illustrated in FIG.7(a), i.e., a situation where the first vehicle 12 a is trying to mergeinto the main lane vehicles by associating the first positionalinformation with map information stored in advance. Furthermore, thedetermining unit 332 derives the density of the other vehicles 12 on themain lane on the basis of the second positional information. Thiscorresponds to counting the number of other vehicles 12 running on amerging section 250 of the main lane. In a case where the density islower than a threshold value, the determining unit 332 determines thatthe automatic steering mode can be maintained. Meanwhile, in a casewhere the density is equal to or higher than the threshold value, thedetermining unit 332 determines that it is difficult to maintain theautomatic steering mode. This corresponds to a situation where it isdifficult for the first vehicle 12 a that is running on the merging laneto merge in the automatic steering mode because of a traffic jam on themerging section 250 of the main lane. Note that the determining unit 332may derive an average of distances between other vehicles 12 on the mainlane on the basis of the second positional information. In this case, ina case where the distance is longer than a threshold value, thedetermining unit 332 determines that the automatic steering mode can bemaintained, whereas in a case where the distance is equal to or shorterthan the threshold value, it is determined that it is difficult tomaintain the automatic steering mode.

This corresponds to determining to switch the automatic steering mode tothe manual steering mode on the basis of the positional information ofthe other vehicles 12 and corresponds to transition to the switchingmode along the line L1 of FIG. 6. FIG. 7(b) will be described later. SeeFIG. 5 again. The determining unit 332 changes a current operation modefrom the automatic steering mode to the switching mode, and the processunit 312 manages the switching mode as the current operation mode.Furthermore, the determining unit 332 notifies the notification unit 334of the change to the switching mode.

The notification unit 334 supplies a signal for prompting the driver toperform switching to the manual steering mode to the display unit 304via the I/O unit 310 in a case where the notification unit 334 isnotified of the change to the switching mode, i.e., in a case where thedetermining unit 332 determines to switch to the switching mode. Whenthe display unit 304 receives the signal via the I/O unit 310, thedisplay unit 304 causes a message prompting the driver to performswitching to the manual steering mode to be displayed on the display.

When the driver agrees with this message and presses down the modeswitch 306, a switching signal is transmitted to the vehicle controldevice 300 as described above. Furthermore, the switching signal istransmitted from the vehicle control device 300 to the automatic drivingcontrol device 302. Upon receipt of the switching signal, the automaticdriving control device 302 switches the vehicle 12 from the automaticsteering mode to the manual steering mode. When the process unit 312receives the switching signal in the vehicle control device 300, theprocess unit 312 manages the manual steering mode as the currentoperation mode.

Meanwhile, there are cases where the driver does not press down the modeswitch 306 even in a case where the message prompting the driver toperform switching to the manual steering mode is displayed on thedisplay. In order to cope with such cases, the process unit 312 measuresa travelling period or a travelling distance from output of the signalprompting the driver to perform switching to the manual steering mode.In a case where a certain travelling period or a certain travellingdistance passes without receipt of the switching signal from the modeswitch 306, the process unit 312 determines to stop the vehicle 12 inthe automatic steering mode. The process unit 312 supplies a result ofdetermination indicating stoppage of the vehicle 12 to the automaticdriving control device 302 via the I/O unit 310. Upon receipt of theresult of determination, the automatic driving control device 302 stopsthe vehicle 12 to a safe place.

In FIG. 7(a), the vehicle control device 300 (not illustrated) mountedin the first vehicle 12 a displays, at a point P1, the message promptingthe driver to perform switching to the manual steering mode. In a casewhere the driver presses down the mode switch 306 while the firstvehicle 12 a is running on an authority handover section 252, the firstvehicle 12 a is switched from the automatic steering mode to the manualsteering mode. Accordingly, a period or a distance corresponding to theauthority handover section 252 is secured so that the driver whoconfirms the message can press down the mode switch 306.

Meanwhile, FIG. 7(b) illustrates, for comparison with the presentembodiment, a case where an autonomous sensor determines that it isdifficult to maintain the automatic steering mode. Since an area that isdetectable by the autonomous sensor is narrow as described above, themessage prompting the driver to perform switching to the manual steeringmode is displayed at a point P2. This forces the driver to give aninstruction to switch the mode while the first vehicle 12 a is runningon an authority handover section 254. The authority handover section 254is shorter than the authority handover section 252. See FIG. 5 again.

The determining process in the determining unit 332 may be performed asfollows. A packet signal received by the terminal device 14 sometimesincludes event information. The event information is informationindicative of an unusual traffic condition such as informationindicating that a one-side alternate traffic section is set due toconstruction or information indicating that flag signaling istemporarily performed at a traffic intersection. The receiving unit 330receives the event information from the terminal device 14 via the I/Ounit 310. The receiving unit 330 supplies the event information to thedetermining unit 332. Upon receipt of the even information, thedetermining unit 332 specifies positional information indicated by theevent information. This positional information indicates, for example, aplace of a one-side alternate traffic section and is referred to as a“third positional information” for convenience of description. Thedetermining unit 332 determines that it is difficult to maintain theautomatic steering mode in a case where the first positional informationis within a predetermined range from the third positional information.That is, the determining unit 332 determines whether to switch theautomatic steering mode to the manual steering mode on the basis of theevent information.

An operation of the vehicle control device 300 configured as above isdescribed below. FIG. 8 is a flow chart illustrating a procedure ofprocesses performed in the automatic steering mode by the vehiclecontrol device 300. The terminal device 14 receives a packet signal(S10). The process unit 312 executes the automatic steering mode (S12).In a case where the automatic steering mode is not possible (N in S14),the determining unit 332 determines to switch to the switching mode(S16). In a case where the automatic steering mode is possible (Y inS14), Step S16 is skipped.

FIG. 9 is a flow chart illustrating a procedure of processes performedin the switching mode by the vehicle control device 300. The terminaldevice 14 receives a packet signal (S30). The process unit 312 executesthe switching mode (S32). In a case where the automatic steering mode ispossible (Y in S34), the process unit 312 determines to switch to theautomatic steering mode (S38). In a case where the automatic steeringmode is not possible (N in S34) and where a switching signal is received(Y in S36), the process unit 312 performs switching to the manualsteering mode (S40). In a case where no switching signal is received (Nin S36), Step 40 is skipped.

According to the embodiment of the present disclosure, since it isdetermined whether or not to switch the automatic steering mode to themanual steering mode on the basis of a packet signal received from awireless device mounted in another vehicle, the determining process canbe performed earlier. Furthermore, since the determining process can beperformed earlier, the automatic steering mode can be smoothly switchedto the manual steering mode. Furthermore, since a packet signal receivedfrom a wireless device mounted in another vehicle is used, informationon a wider range than an autonomous sensor can be acquired. Furthermore,since a packet signal received from a wireless device mounted in anothervehicle is used, it is possible to avoid difficulty of continuation ofthe automatic steering mode based on a positional relationship with theother vehicle. Furthermore, it is possible to avoid difficulty ofcontinuation of the automatic steering mode based on the eventinformation.

Embodiment 2

Next, Embodiment 2 of the present disclosure is described. Embodiment 2relates to a vehicle control device mounted in a vehicle that can switchbetween an automatic steering mode and a manual steering mode and usespositional information acquired in a communication system, as inEmbodiment 1. Conventionally, in a case where merging occurs as inEmbodiment 1, a device that controls travelling of all of a plurality ofvehicles related to the merging is provided, and each of the vehiclesruns in accordance with a command from the device. However, in a casewhere a vehicle in the automatic steering mode merges, parameters fordetermining a travelling route and a travelling speed (hereinaftercollectively referred to as “travelling schedule”) are affected by notonly the position and speed, but also other factors. The other factorsare, for example, the presence of an obstacle, characteristics of avehicle (acceleration performance and braking performance),characteristics and preference (e.g., preference concerning aninter-vehicle distance) of a driver, and the like. In a case where avehicle runs in accordance with a command, it is difficult to create thetravelling schedule in consideration of these other factors.

In view of this, in a case where a vehicle is running on a merging lane,a vehicle control device according to the present embodiment createstravelling schedule information on the basis of positional informationof another vehicle running on a main lane that is acquired throughcommunication so that the vehicle can merge into a place ahead or behindthe other vehicle running on the main lane in the automatic steeringmode. Furthermore, the vehicle control device notifies the other vehiclerunning on the main lane of schedule of merging by transmitting thetravelling schedule information through inter-vehicle communication. Theother vehicle recognizes the presence of the vehicle that is trying tomerge on the basis of the travelling schedule information and controlstravelling in accordance with the travelling schedule information. Acommunication system 100 according to Embodiment 2 is similar to thatillustrated in FIGS. 1 through 4, and differences are mainly describedbelow. Note that in a case where there is no other vehicle running onthe main lane in the automatic steering mode at a merging timing,switching between the automatic steering mode and the manual steeringmode need just be executed by performing a determining process inaccordance with the procedure of Embodiment 1.

FIG. 10 is a diagram illustrating a configuration of a vehicle 12according to Embodiment 2 of the present disclosure. The vehicle 12includes a terminal device 14, a vehicle control device 300, anautomatic driving control device 302, a display unit 304, and a modeswitch 306. The vehicle control device 300 includes an I/O unit 310 anda process unit 312, and the process unit 312 includes a receiving unit330, a determining unit 332, a notification unit 334, a generation unit336, and a transmitting unit 338. The automatic driving control device302 includes an I/O unit 320 and a process unit 322.

The receiving unit 330 receives first positional information and secondpositional information as described above. The receiving unit 330supplies the first positional information and the second positionalinformation to the generation unit 336. The generation unit 336 receivesthe first positional information and the second positional informationfrom the receiving unit 330. The generation unit 336 generatestravelling schedule information of the host vehicle 12 in the automaticsteering mode on the basis of the first positional information and thesecond positional information before a determining process in thedetermining unit 332. In generation of the travelling scheduleinformation, the current position, travelling direction, and travellingspeed in the first positional information and the second positionalinformation are used. The generation unit 336 generates the travellingschedule information by executing (1) creation of reference scheduleinformation, (2) determination of interference with another vehicle 12on a main lane, and (3) modification of the reference scheduleinformation. These processes are described below with reference to FIG.11.

FIG. 11 is a diagram for explaining an outline of a process performed bythe process unit 312. FIG. 11 illustrates a merging lane and a main laneof an expressway or the like as in FIG. 7(a), and a first vehicle 12 awhich is the host vehicle 12 is running on the merging lane. Secondthrough eighth vehicles 12 b through 12 h are running on the main laneand are sometimes collectively referred to as “other vehicles 12”.

(1) Creation of Reference Schedule Information

The generation unit 336 assumes that the first vehicle 12 a runs at amerging lane regulatory speed from a current position to a mergingsection near end 260. Furthermore, the generation unit 336 assumes thatthe first vehicle 12 a runs from the merging section near end 260 at anacceleration so that the speed thereof increases from the merging laneregulatory speed to a main lane regulatory speed. Furthermore, on theseassumptions, the generation unit 336 derives a distance from the mergingsection near end 260 at a time when the first vehicle 12 a reaches themain lane regulatory speed, i.e., a merging start point 262 and derivesa period taken for the first vehicle 12 a to reach the main laneregulatory speed, i.e., a merging start period.

(2) Determination of Interference with Another Vehicle 12 on Main Lane

The generation unit 336 derives a distance L between another vehicle 12and the merging section near end 260 after elapse of the merging startperiod obtained from the reference schedule information on the basis ofthe position and travelling speed of the other vehicle 12. In a casewhere an absolute value of a difference between the distance L and themerging start point 262 is equal to or shorter than a predetermined safeinter-vehicle distance, the determining unit 332 determines that thefirst vehicle 12 a and the other vehicle 12 interfere with each other.Note that it is also possible to employ an arrangement in which whetherthe first vehicle 12 a merges into a place ahead of the other vehicle 12or a place behind the other vehicle 12 is set in accordance withcharacteristics/preference of a driver and the safe inter-vehicledistance is changed in accordance with the setting.

(3) Modification of Reference Schedule Information

The generation unit 336 creates a non-interference route having a smalldifference from the reference schedule information in a case where thefirst vehicle 12 a and the other vehicle 12 interfere with each other.Specifically, the generation unit 336 derives a speed at which the safeinter-vehicle distance from the other vehicle 12 can be secured aftermerging and at which the first vehicle 12 a runs on the merging lane.Furthermore, the generation unit 336 derives a time at which the firstvehicle 12 a starts acceleration after passing the merging section nearend 260 and acceleration at which the first vehicle 12 a acceleratesfrom the merging lane regulatory speed to the main lane regulatoryspeed. Note that in a case where the time and acceleration cannot becalculated, the generation unit 336 determines that merging isimpossible. Furthermore, the generation unit 336 selects, as a modifiedroute, a route having a small difference from the reference schedule,i.e., having the closest merging start point 262 and calculates themerging start point 262 and merging start period in the selected route.Finally obtained reference schedule information corresponds to thetravelling schedule information. Note that the generation unit 336 maygenerate the travelling schedule information so that the first vehicle12 a merges into a place ahead of the other vehicle 12 running in theautomatic steering mode among the other vehicles 12 running on the mainlane. See FIG. 10 again.

As a result of these processes, essential information in the travellingschedule information generated by the generation unit 336 includesinformation on the merging start period during travelling on the merginglane. The merging start period indicates seconds before the start ofmerging. Optional information in the travelling schedule informationincludes information on a direction (up or down), a distance to themerging section near end 260, the merging start point 262, a mergingvehicle position, a merging agreement situation, and a target speed atthe time of completion of merging. The merging start point 262 indicatesa distance from the merging section near end 260, the merging vehicleposition indicates between which other vehicles 12 the first vehicle 12a enters by using a vehicle ID, and the merging agreement situationindicates a situation of agreement with the other vehicles 12 betweenwhich the first vehicle 12 a enters.

The essential information indicates, for example, “merging state periodduring travelling on the merging lane: 20 s”. The optional informationindicates “direction: up”, “distance to the merging section near end260: 200 m”, “merging start point 262: 70 m”, “merging vehicle position:ahead of vehicle ID “Y””, “merging agreement situation: not approved byvehicle ID “Y””, and “target speed at the time of completion of merging:indefinite”. The generation unit 336 supplies the travelling scheduleinformation to the transmitting unit 338.

The transmitting unit 338 receives the travelling schedule informationgenerated in the generation unit 336. The transmitting unit 338transmits the travelling schedule information to the terminal device 14via the I/O unit 310. The terminal device 14 broadcasts a packet signalincluding the travelling schedule information. The terminal device 14receives a packet signal including a result indicating whether or notanother vehicle 12 approves of the travelling schedule informationincluded in the packet signal thus broadcast. The terminal device 14transmits the result to the receiving unit 330 via the I/O unit 310.

The receiving unit 330 receives a result of approval. The receiving unit330 receives a result indicating whether or not another vehicle approvesof the travelling schedule information transmitted by the transmittingunit 338. Essential information of the result includes a result ofdetermination as to whether or not merging is possible and indicates,for example, “vehicle ID: X OK”. Optional information of the resultincludes a direction, a distance to the merging section near end 260, aperiod taken to reach the merging section near end 260, a forwardinter-vehicle distance, a backward inter-vehicle distance, a right-sidesituation, and a left-side situation. The optional informationindicates, for example, “direction: up”, “distance to the mergingsection near end 260: 320 m”, “period taken to reach the merging sectionnear end 260: 15 seconds”, “forward inter-vehicle distance: 120 m”, and“backward inter-vehicle distance: 50 m”. The receiving unit 330 suppliesthe result to the generation unit 336 and the determining unit 332.

The generation unit 336 confirms the result and generates the travellingschedule information again by performing the aforementioned processes.In a case where reference schedule information is created for the secondor subsequent time, the reference schedule information created in theprevious processes is used. For example, the essential informationindicates “merging state period during travelling on the merging lane:18 s”. The optional information indicates “direction: up”, “distance tothe merging section near end: 150 m”, “merging start point 262: 75 m”,“merging vehicle position: ahead of vehicle ID “Y””, “merging agreementsituation: not approved by vehicle ID “Y””, and “target speed at thetime of completion of merging: 80 km/h”. The generation unit 336supplies the travelling schedule information to the transmitting unit338. The generation unit 336 supplies the travelling scheduleinformation to the transmitting unit 338 in a manner similar thatdescribed above.

The determining unit 332 determines to switch the automatic steeringmode to the manual steering mode in a case where the result ofdetermination as to whether or not merging is possible that is includedin the result is No (i.e., Another vehicle does not approve of thetravelling schedule information). That is, the determining unit 332determines that it is difficult to maintain the automatic steering mode.Subsequent processes are similar to those described above.

An operation of the vehicle control device 300 configured as above isdescribed. FIG. 12 is a sequence diagram illustrating a mergingprocedure performed between vehicles 12 according to Embodiment 2 of thepresent disclosure. The second vehicle 12 b transmits positionalinformation to the first vehicle 12 a (S50). The first vehicle 12 adetermines a merging position (S52) and generates travelling scheduleinformation (S54). The first vehicle 12 a transmits the travellingschedule information to the second vehicle 12 b (S56). The secondvehicle 12 b determines whether or not merging is possible (S58). Thesecond vehicle 12 b transmits a result including a result ofdetermination by the second vehicle 12 b as to whether or not merging ispossible to the first vehicle 12 a (S60). The first vehicle 12 adetermines a merging position (S62) and generates travelling scheduleinformation (S64). The first vehicle 12 a transmits the travellingschedule information to the second vehicle 12 b (S66). The secondvehicle 12 b determines whether or not merging is possible (S68).

FIG. 13 is a sequence diagram illustrating another merging procedureperformed among vehicles 12 according to Embodiment 2 of the presentdisclosure. The second vehicle 12 b transmits positional information tothe first vehicle 12 a (S100), and the third vehicle 12 c transmitspositional information to the first vehicle 12 a (S102). The firstvehicle 12 a determines a merging position (S104) and generatestravelling schedule information (S106). The first vehicle 12 a transmitsthe travelling schedule information to the second vehicle 12 b and thethird vehicle 12 c (S108 and S110). The second vehicle 12 b determineswhether or not merging is possible (S112), and the third vehicle 12 cdetermines whether or not merging is possible (S114).

The second vehicle 12 b transmits a result, indicating whether thesecond vehicle 12 b approves or disapproves of travelling scheduleinformation, to the first vehicle 12 a (S116), and the third vehicle 12c transmits a result, indicating whether the third vehicle 12 c approvesor disapproves of travelling schedule information, to the first vehicle12 a (S118). The first vehicle 12 a determines a merging position (S120)and generates travelling schedule information (S122). The first vehicle12 a transmits the travelling schedule information to the second vehicle12 b and the third vehicle 12 c (S124 and S126). The second vehicle 12 bdetermines whether or not merging is possible (S128), and the thirdvehicle 12 c determines whether or not merging is possible (S130).

FIG. 14 is a flow chart illustrating a travelling schedule informationgenerating procedure performed by the vehicle control device 300according to Embodiment 2 of the present disclosure. In a case wherethere is no reference schedule information (N in S150), the generationunit 336 creates reference schedule information (S152). In a case wherethere is reference schedule information (Y in S150), Step S152 isskipped. In a case where there is interference (Y in S154), thegeneration unit 336 modifies the reference schedule information (S156).In a case where there is no interference (N in S154), Step S156 isskipped.

According to the embodiment of the present disclosure, since travellingschedule information is generated on the basis of positional informationof another vehicle included in a received packet signal, the travellingschedule information can be generated earlier. Furthermore, sincecharacteristics/preference of a driver are reflected in generation ofthe travelling schedule information, these characteristics/preferencecan be reflected. Furthermore, since a result, indicating whetheranother vehicle approves or disapproves of the travelling scheduleinformation, is received, it can be recognized whether or not thetravelling schedule information has been accepted. Furthermore, since itis determined to switch the automatic steering mode to the manualsteering mode in a case where the result indicating that the othervehicle disapproved of the travelling schedule information, it can berecognized that the travelling schedule information has not beenaccepted. Furthermore, since the automatic steering mode is switched tothe manual steering mode in a case where the travelling scheduleinformation has not been accepted, it is possible to prevent occurrenceof collision in the automatic steering mode. Furthermore, since avehicle merges into a place ahead of another vehicle that is in theautomatic steering mode, safety can be secured. Furthermore, it ispossible to realize safer and smoother merging with no rapidacceleration or deceleration based on characteristics of a host vehicle.

The present disclosure has been described above on the basis of theembodiments. The embodiments are examples, and it will be understood bya person skilled in the art that a combination of constituent elementsor processes can be modified in various ways and that such modificationsare also encompassed within the scope of the present disclosure.

An outline of one aspect of the present disclosure is as follows. Avehicle control device according to an aspect of the present disclosureis a vehicle control device that is capable of being mounted in avehicle, including: a receiver that receives information from a wirelessdevice mounted in another vehicle; a determiner that determines whetheror not to switch an automatic steering mode to a manual steering mode onthe basis of the information received by the receiver; and a notifierthat prompts a driver of the vehicle to switch the automatic steeringmode to the manual steering mode in a case where the determinerdetermines to switch the automatic steering mode to the manual steeringmode.

According to this aspect, it is determined whether or not an automaticsteering mode is switched to a manual steering mode on the basis ofinformation supplied from a wireless device mounted in another vehicle,the determining process can be performed earlier.

The vehicle control device may be arranged such that the receiverreceives event information as the information and the determinerdetermines whether or not to switch the automatic steering mode to themanual steering mode on basis of the event information received by thereceiver. In this case, it is possible to avoid difficulty ofcontinuation of the automatic steering mode based on the eventinformation.

The vehicle control device may be arranged such that the receiverreceives positional information of the other vehicle as the informationand the determiner determines whether or not to switch the automaticsteering mode to the manual steering mode on basis of the positionalinformation of the other vehicle received by the receiver. In this case,it is possible to avoid difficulty of continuation of the automaticsteering mode based on a positional relationship with another vehicle.

The vehicle control device may be arranged such that the receiverreceives positional information of the other vehicle as the information.And the vehicle control device may be arranged to further include agenerator that generates travelling schedule information of the vehiclein the automatic steering mode on the basis of the positionalinformation of the other vehicle received by the receiver before thedetermination in the determiner. In this case, since the travellingschedule information is generated on the basis of the receivedpositional information of the other vehicle, the travelling scheduleinformation can be generated earlier.

The vehicle control device may be arranged to further include atransmitter that transmits, by broadcast, the travelling scheduleinformation generated by the generator, and the receiver may receive, asthe information, a result indicating whether or not the other vehicleapproves of the travelling schedule information transmitted by thetransmitter. In this case, since a result of approval is received, itcan be recognized whether or not the travelling schedule information hasbeen accepted.

The vehicle control device may be arranged such that the determinerdetermines to switch the automatic steering mode to the manual steeringmode in a case where the result, received by the receiver, indicatesthat the other vehicle does not approve of the travelling scheduleinformation. In this case, since it is determined to switch theautomatic steering mode to the manual steering mode in a case where theresult of approval is disapproval, it can be recognized that thetravelling schedule information has not been accepted.

The vehicle control device may be arranged such that at least one of thereceiver, the determiner, and the notifier includes a processor.

In Embodiments 1 and 2 of the present disclosure, a case where a vehicle12 running on a merging lane merges into a main lane is used as anexample. However, the present disclosure is not limited to this and isapplicable, for example, to a case where a vehicle 12 is required tomake a lane change within a predetermined distance. In this case, theautomatic steering mode is switched to the manual steering mode in acase where it is difficult for the vehicle 12 to make a lane change inan automatic running mode because a line of vehicles is long and aninter-vehicle distance is short on a lane to which the vehicle 12 isabout to move. According to this modification, an application range canbe widened.

What is claimed is:
 1. A vehicle control device that is capable of beingmounted in a vehicle, comprising: a receiver that receives informationfrom a wireless device mounted in another vehicle; a determiner thatdetermines whether or not to switch an automatic steering mode to amanual steering mode on basis of the information received by thereceiver; and a notifier that prompts a driver of the vehicle to switchthe automatic steering mode to the manual steering mode in a case wherethe determiner determines to switch the automatic steering mode to themanual steering mode.
 2. The vehicle control device according to claim1, wherein the receiver receives event information as the information,and wherein the determiner determines whether or not to switch theautomatic steering mode to the manual steering mode on basis of theevent information received by the receiver.
 3. The vehicle controldevice according to claim 1, wherein the receiver receives positionalinformation of the other vehicle as the information, and wherein thedeterminer determines whether or not to switch the automatic steeringmode to the manual steering mode on basis of the positional informationof the other vehicle received by the receiver.
 4. The vehicle controldevice according to claim 1, wherein the receiver receives positionalinformation of the other vehicle as the information, and the vehiclecontrol device further comprises a generator that generates travellingschedule information of the vehicle in the automatic steering mode onbasis of the positional information of the other vehicle received by thereceiver before the determination in the determiner.
 5. The vehiclecontrol device according to claim 4, further comprising a transmitterthat transmits, by broadcast, the travelling schedule informationgenerated by the generator, wherein the receiver receives a result, asthe information, which indicates whether or not the other vehicleapproves of the travelling schedule information transmitted by thetransmitter.
 6. The vehicle control device according to claim 5, whereinthe determiner determines to switch the automatic steering mode to themanual steering mode in a case where the result, received by thereceiver, indicates that the other vehicle does not approve of thetravelling schedule information.
 7. The vehicle control device accordingto claim 1, wherein at least one of the receiver, the determiner, andthe notifier includes a processor.